Keyless chucks operable to retain a work piece therein by rotational movement of an outer sleeve relative to the body of the chuck is known. Many of these keyless chucks incorporate a locking feature to prevent the sleeve from opening the chuck during use. One type of locking feature is an automatic locking feature wherein as the jaws are tightened about the work piece, the sleeve, upon receiving a tightening torque in excess of a predetermined value, will lock or detent into a locked position that inhibits loosening of the chuck. This automatic locking feature provides for a quick and easy way of locking the work piece in the chuck. This automatic locking feature, however, may open during use in certain situations, such as abrupt stall, high vibration and when the sleeve rubs on an object while working in a tight space. Thus, while this type of automatic locking feature provides for a quick and easy way of securing a work piece in a chuck, it only provides moderate performance and may be susceptible to opening during use.
A second type of locking feature that can be utilized is a manual locking feature. With this type of locking feature, a user is required to tighten the chuck onto the work piece and then manually lock the chuck sleeve via axial movement of the sleeve, or a connected component, with respect to the body. This type of locking chuck provides excellent performance in that the locking sleeve is prevented from loosening during operation by being rotationally fixed relative to the body. The use of the manually locking feature, however, adds an extra step to the use of the tool incorporating the chuck. Thus, while greater performance can be achieved, the use of such a chuck is more time consuming.
Thus, the current keyless locking chucks require a choice between utilizing one that incorporates an automatic lock or one that incorporates a manual locking feature. Accordingly, when selecting a chuck, a trade off must be made between choosing one that is quicker to operate but provides a less secure locking feature and may loosen during use and choosing one that provides superior locking performance but requires an additional step to achieve this benefit.